The Cancer Blog

May 11, 2009, 5:12 AM CT

Conflicts of interest in many cancer studies

A new analysis finds that a considerable number of clinical cancer studies published in respected medical journals have financial connections to pharmaceutical companies. Reported in the June 15, 2009 issue of CANCER, a peer-evaluated journal of the American Cancer Society, the study indicates that conflicts of interest may cause some scientists to report biased results that are favorable to companies.

Ties between clinical scientists and companies that make medical devices and drugs have become increasingly complex and controversial, especially as more scientists compete for scarce federal research funds. In addition to using industry money to support their research, some researchers receive consulting fees, own stock and hold positions within companies that profit from selling the very products they are investigating. These conflicts of interest have raised concerns that studies with ties to industry are biased and are not designed to provide a true test of medical therapies. A number of medical journals now require scientists to disclose potential conflicts of interest in the articles they submit for publication.

To get sense of the frequency and impact of conflicts of interest in clinical cancer research, Dr. Reshma Jagsi of the University of Michigan and his colleagues evaluated cancer studies appearing in eight highly regarded journals in 2006. These journals included the New England Journal (NEJM); JAMA; the Lancet; the Journal of Clinical Oncology; the Journal of the National Cancer Institute; Lancet Oncology; Clinical Cancer Research; and CANCER........ Posted by: Andria      Read more         Source

April 30, 2009, 9:37 PM CT

Cancer-obesity link

A new link between body fat and cancer identified by a Michigan State University researcher underscores obesity's health risk and could lead to new cancer therapy and prevention strategies.

Jenifer Fenton, an MSU food science and human nutrition researcher with the Michigan Agricultural Experiment Station, identified the correlation between obesity and colon cancer, the third-leading killer of Americans, in part by examining tissue hormones.

Working with MSU/MAES physiologist Julia Busik and biologist Fay Hansen-Smith of Oakland University in Rochester, Mich., Fenton examined a key hormone found in fat tissue and thought to promote cancer. Her conclusions are published in a study today in the journal Carcinogenesis.

Leptin - a fat cell-derived hormone regulating body energy - is higher in obese individuals. Fenton's study is the first to demonstrate that, at higher levels, leptin induces premalignant colon cells to produce more of a growth factor that can increase blood supply to early cancer cells - promoting tumor growth and cancer progression.

"Adipose tissue, or fat, is recognized as a significant risk factor for diabetes and heart disease, but the role of adipose tissue in cancer risk is less understood," Fenton said. "Abdominal fat in particular seems to be linked to the greatest risk for cancer. As your waist-to-hip ratio increases, so does your risk for cancer, particularly breast, colon and endometrial cancers"......... Posted by: Andria      Read more         Source

April 30, 2009, 5:08 AM CT

A new weapon against brain cancer

An unlikely multidisciplinary scientific collaboration has discovered that an electronic nose developed for air quality monitoring on Space Shuttle Endeavour can also be used to detect odour differences in normal and malignant brain cells. The results of the pilot study open up new possibilities for neurosurgeons in the fight against brain cancer.

Neurosurgeons from the City of Hope Cancer Center, along with researchers from the Brain Mapping Foundation in West Hollywood and the Jet Propulsion Laboratory (JPL) in Pasadena, used NASA's electronic nose to investigate the role of cellular odours in cellular trafficking, brain cancer metastasis, stem cell migration, and the potential of the device to be used for intraoperative imaging.

The electronic nose, which is to be installed on the International Space Station in order to automatically monitor the station's air, can detect contaminants within a range of one to approximately 10,000 parts per million. In a series of experiments, the Brain Mapping Foundation used NASA's electronic nose to sniff brain cancer cells and cells in other organs. Their data demonstrates that the electronic nose can sense differences in odour from normal versus malignant cells. These experiments will help pave the way for more sophisticated biochemical analysis and experimentation......... Posted by: Andria      Read more         Source

April 29, 2009, 5:18 AM CT

Diagnostic advance in head and neck cancer

Pharmacy scientists at Oregon State University today announced the discovery of a genetic regulator that is expressed at higher levels in the most aggressive types of head and neck cancers, in work that may help to identify them earlier or even offer a new treatment at some point in the future.

This "transcriptional regulator" is called CTIP2, and in recent research has been demonstrated to be a master regulator that has important roles in a number of biological functions, ranging from the proper development of enamel on teeth to skin formation and the possible therapy of eczema or psoriasis.

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2671404.

In the newest study, published recently in PLoS ONE, a professional journal, researchers found for the first time that levels of CTIP2 were more than five times higher in the "poorly differentiated" tumor cells that caused the most deadly types of squamous cell carcinomas in the larynx, throat, tongue and other parts of the head. There was a high connection between greater CTIP2 expression and the aggressive nature of the cancer.

Head and neck squamous cell cancers are the sixth most common cancers in the world, the scientists said in their study, and a significant cause of mortality. In 2008, cancers of the oral cavity and pharynx alone accounted for 35,310 new cases in the United States and 7,590 deaths. They have been associated with such things as tobacco use and alcohol consumption......... Posted by: Andria      Read more         Source

April 27, 2009, 5:23 AM CT

Reducing prostate cancer and disease

Statins, drugs widely prescribed to lower cholesterol, may have protective effects on prostate health. This large Mayo Clinic cohort study looked at three different aspects of urological health -- prostate cancer, erectile dysfunction and prostate enlargement. Initial research results are being presented April 25-30, 2009, at the American Urological Association (AUA) meeting in Chicago.

VIDEO ALERT: Additional audio and video resources, including excerpts from an interview with Drs. St. Sauver, Karnes and Breau describing the research, are available on the Mayo Clinic News Blog,. These materials are also subject to embargo, but appears to be accessed in advance by journalists for incorporation into stories. The password for this post is password Statin049.

These Mayo Clinic study findings came from data in the Olmsted County Study of Urinary Health Status among Men, a large cohort study of men living in Olmsted County, Minn. This study has followed 2,447 men ages 40 to 79 from 1990 to the present to assess various urologic outcomes among aging men.

"A main advantages of this large cohort study is that the men have participated in this study for over 15 years. Because of this, we have the ability to look at associations between statin use, how long statins were used and multiple aspects of urologic function," says Jennifer St. Sauver, Ph.D., Mayo Clinic epidemiologist and study author......... Posted by: Andria      Read more         Source

April 27, 2009, 5:14 AM CT

How to improve immune response to cancer

A team of researchers at The Campbell Family Institute for Breast Cancer Research (CFIBCR) at Princess Margaret Hospital and international collaborators have discovered how to trigger an improved immune response to cancer that could be included in new clinical trials that use a patient's own cells to destroy tumours.

The findings, published online today in Nature Medicine (DOI: 10.1038/nm.1953), demonstrate the tantalizing potential of immunotherapy in cancer therapy, says principal investigator Dr. Pamela Ohashi, co-director, CFIBCR.

In the lab study, the researchers combined interleukin-7 (IL-7) a key component of the immune system with a viral vaccine to improve the ability of the cells of the immune system to attack tumours. The result was clear: The combination boosted immunity to tumours.

"We are extremely excited because our research has revealed the unexpected ways IL-7 works to break down barriers that naturally block the immune response to tumours. This is important because current vaccine approaches for immune treatment induce a response in just 1% to 3% of patients," says Dr. Ohashi, a senior scientist in signaling biology who holds a Canada Research Chair in Autoimmunity and Tumour Immunity. She is also a Professor, University of Toronto, in the Department of Medical Biophysics and Immunology. "......... Posted by: Andria      Read more         Source

April 21, 2009, 5:31 AM CT

Genetic Variants Predict Recurrence of Bladder Cancer

Researchers at The University of Texas M. D. Anderson Cancer Center have discovered genetic variations in the inflammation pathway that reduce the likelihood of recurrence and increase survival of patients with non-muscle invasive bladder cancer (NMIBC) who are treated with mainstream treatment.

Patients with risk-reducing genotypes were 84 percent less likely to have their disease recur after therapy with Bacillus Calmette-Guerin (BCG), the prevailing immunotherapy to prevent high-risk NMIBC patients from developing recurrence. The recurrence-free median survival time among these patients was 96.7 months compared with 47 months among those with the more typical genotype, the team reported at the 100th Annual Meeting of the American Association for Cancer Research.

"The future purpose of this kind of study is personalized cancer treatment," said senior author Xifeng Wu, M.D., Ph.D., a professor in the Department of Epidemiology at M. D. Anderson. "This genetic information is an essential step toward constructing a blueprint that will determine therapy response and follow-up strategy".

Currently, the primary therapy for NMIBC is transurethral resection - surgical removal of the tumor tissues from bladder - combined with chemotherapy or immunotherapy such as BCG injection. Overall, the recurrence rate is around 50 percent over four years......... Posted by: Andria      Read more         Source

April 16, 2009, 5:12 AM CT

A gel to treat esophageal cancer

Gastroenterologists at Rush University Medical Center are studying the safety and efficacy of a new system for delivering chemotherapy for patients with esophageal cancer, a rare, but deadly disease that attacks the throat. The unique drug treatment delivers a highly concentrated dose of chemotherapy injected directly on to the hard-to-reach tumors in the esophagus non-surgically. Scientists at Rush are trying to determine if the gel therapy can reduce the size of the malignant tumors.

Patients diagnosed with esophageal cancer are commonly diagnosed at very advanced stages and not only have to undergo chemoradiation treatment, but may also have an esophagectomy, which is a surgical procedure to remove a part of or the entire esophagus.

"Patients with esophageal cancer have very few therapy options and life expectancy can be less than two years from first diagnosis," said Dr. Sohrab Mobarhan, principal investigator of the study and clinical director of the Coleman Foundation Comprehensive Clinic for Gastrointestinal Cancers at Rush. "This also could potentially be a viable therapy option for patients who have inoperable tumors located in their esophagus." .

The investigational drug, called OncoGel, is made of two major components, the ReGel drug delivery system, which is a gel made up of ingredients used in biodegradable stitches, and paxclitaxel, a well established, FDA-approved anti-cancer chemotherapy agent. Patients receive a one-time injection of OncoGel during an endoscopy......... Posted by: Andria      Read more         Source

April 13, 2009, 1:53 PM CT

Genetics alone is poor indicator for drug response

In certain respects, cells are less like machines and more like people. True, they have lots of components, but they also have lots of personality. For example, when specific groups of people are studied in aggregate (conservatives, liberals, atheists, evangelicals), they appear to be fairly uniform and predictable. But when looked at one person at a time, individuals often break the preconceptions.

Same with cells.

Scientists tend to identify characteristics of particular cells by looking at millions at a time. As a result, they'll find that, say, "group A" responds very well to a particular cancer therapy, whereas "group B" does not. They will then often compare group A to group B to find out why.

But often ignored is that not every cell in either group behaves in ways that the aggregate indicates. In a group of cells shown to be vulnerable to a particular cancer therapy, perhaps 10 percent resist it while 90 percent succumb. While scientists have offered various explanations for this, few have studied it.

Now a group of researchers in the lab of Harvard Medical School Professor of Systems Biology Peter Sorger have studied such "outlier" cells in the context of a new and highly touted cancer drug. They have observed that vastly disparate reactions occur within genetically homogeneous cell groups. These discrepancies result from protein levels that vary from cell to cell, even among cells that are identical genetic twins. What's more, these protein levels and their subsequent traits can be passed down to daughter cellsa heritability that has nothing to do with genetics......... Posted by: Andria      Read more         Source

April 13, 2009, 1:27 PM CT

When cancer cells can't let go

Like a climber scaling a rock face, a migrating cancer cell has to keep a tight grip on the surface but also let go at the right moment to move ahead. Chan et al. reveal that the focal adhesion kinase (FAK) coordinates these processes to permit forward movement. The study will be published online April 13 (www.jcb.org) and will appear in the April 20 print issue of the Journal of Cell Biology

Crawling cancer cells send out extensions called invadopodia. By releasing enzymes that dissolve the extracellular matrix (ECM), invadopodia clear a path for the cell to wriggle through. As they move, cancer cells get traction by temporarily attaching to the ECM through focal adhesions. FAK spurs focal adhesions to disengage, and it is more abundant in metastatic tumors. Whether FAK also regulates invadopodia was unknown.

When Chan et al. removed FAK, breast cancer cells were much less invasive. But to the team's surprise, the FAK-lacking cells sprouted extra invadopodia. The cells also sported large focal adhesions that were especially sticky. The protein Src serves as FAK's helper. FAK and Src work together to phosphorylate tyrosines in proteins such as paxillin, which then disassemble the focal adhesion. But the team observed that in cells missing FAK, the phosphorylated proteins accumulated in invadopodia. Src's localization reflects this difference. In control cells, Src accumulated in focal adhesions. In FAK's absence, Src headed to the invadopodia......... Posted by: Andria      Read more         Source

April 6, 2009, 10:14 PM CT

Breakthrough model for human cancer

AVEO Pharmaceuticals, Inc., a biopharmaceutical company leveraging breakthrough discoveries in cancer biology to discover, develop and commercialize targeted oncology therapies, today announced findings from its novel human-in-mouse (HIM) cancer model system, in which AVEO successfully created invasive human tumors from primary human breast tissue that develop over time in mice and mimic human tumor behaviors and response. The findings were published this week in the Early Edition of the Proceedings of the National Academy of Sciences

More than 95 percent of oncology drugs entering the clinic fail, due in large part to the lack of predictive animal models in the preclinical development phases. AVEO researchers have developed a sophisticated cancer biology platform that provides models of human cancer more relevant than traditional mouse models known as xenografts. In the AVEO HIM model, normal human breast tissue is engineered to express oncogenes and is then introduced into mice where it forms human breast tissue in the mouse mammary microenvironment. The tumors which then develop spontaneously acquire common and distinct mutations during tumor progression. This process results in human tumors in mice that reflect their human counterparts in that they differ slightly from one instance to another, exhibiting natural genetic variation akin to that seen in patients......... Posted by: Andria      Read more         Source

March 30, 2009, 5:20 AM CT

The new tumor suppressor gene

National Institutes of Health (NIH) scientists have identified a gene that suppresses tumor growth in melanoma, the deadliest form of skin cancer. The finding is reported today in the journal Nature Genetics as part of a systematic genetic analysis of a group of enzymes implicated in skin cancer and a number of other types of cancer.

The NIH analysis observed that one-quarter of human melanoma tumors had changes, or mutations, in genes that code for matrix metalloproteinase (MMP) enzymes. The findings lay the foundation for more individualized cancer therapy strategies where MMP and other key enzymes play a functional role in tumor growth and spread of the disease.

Tumor suppressor genes encode proteins that normally serve as a brake on cell growth. When such genes are mutated, the brake appears to be lifted, resulting in the runaway cell growth known as cancer. In contrast, oncogenes are genes that encode proteins involved in normal cell growth. When such genes are mutated, they also may cause cancer, but they do so by activating growth-promoting signals. Cancer therapies that target oncogenes commonly seek to block or reduce their action, while those aimed at tumor suppressor genes seek to restore or increase their action.

The newly released study may help to explain the disappointing performance of drugs designed to treat cancer by blocking MMP enzymes. Because members of the MMP gene family were believed to be oncogenes and a number of tumors express high levels of MMP enzymes, scientists have spent decades pursuing MMPs as promising targets for cancer therapies. However, when MMP inhibitors were tested in people with a wide range of cancers, the drugs failed to slow -- and in some cases even sped up -- tumor growth......... Posted by: Andria      Read more         Source

March 16, 2009, 8:12 PM CT

Switch May Prevent the Spread of Cancer

Scientists at the University of Pennsylvania School of Medicine have identified a master switch that might prevent cancer cells from metastasizing from a primary tumor to other organs. The switch is a protein that, when in the "on" position, maintains the normal character of cells that line the surface of organs and body cavities. These epithelial cells are the type of cell from which most solid tumors arise. However, when the switch is turned "off" or absent, epithelial cells acquire characteristics of another cell type, called mesenchymal cells, and gain the ability to migrate and move away from the primary tumor. The scientists report their findings in this month's issue of Molecular Cell.

Understanding how this switch works may one day lead to a drug that controls cancer cell metastasis and tissue fibrosis.

This change in cell motility is called the epithelial to mesenchymal transition, or EMT, and is an important process during the development of embryos. But when the transition is aberrantly reactivated in adults it can have dire physiological consequences, leading to cancer metastasis as well as other disease processes such as tissue fibrosis. Fibrotic tissue is a hallmark of organ failure, as in liver cirrhosis or kidney failure.

The master-switch is called the Epithelial Splicing Regulatory Protein, and comes in two closely related versions, ESRP1 and ESRP2. These proteins are able to change how RNAs that are produced from genes are spliced together. This is achieved by splicing different exons -- the sequence of DNA that codes information for protein synthesis -- together in different ways so that there can be more than one messenger RNA (mRNA) produced from the same gene. These mRNAs then go on to make different proteins......... Posted by: Andria      Read more         Source

March 16, 2009, 5:16 AM CT

Five-day radiation treatment of early stage prostate cancer

Preliminary results show that a shortened course of radiation treatment for prostate cancer called stereotactic body radiation treatment (SBRT) provides good PSA response for early-stage prostate cancer and has the same side effects as other therapys, as per a March 15 study in the International Journal of Radiation Oncology*Biology*Physics, the official journal of the American Society for Radiation Oncology (ASTRO). Study authors caution that further follow-up will be necessary to establish that SBRT is as effective in the long term as other proven therapys.

Radiation treatment is an effective way to treat localized prostate cancer. Proven successful therapys include brachytherapy (seed implants) where radiation sources are placed directly into the prostate and external beam radiation treatment where doctors give small daily doses of radiation to the prostate, five days a week, for eight weeks to give enough radiation to kill the cancer cells while sparing nearby healthy tissue.

External beam radiation treatment can be a very effective and minimally invasive therapy. However, the length of therapy can be burdensome for some patients, especially those who live very far from a therapy facility. Doctors have been investigating ways to shorten the course of the therapy through a technique called stereotactic body radiation treatment, where radiation oncologists give a higher dose of radiation every day for five days. Growing biologic evidence also suggests that delivering radiotherapy in this fashion might be more effective for prostate cancer than conventionally protracted courses......... Posted by: Andria      Read more         Source

February 25, 2009, 5:20 AM CT

Nanoscopic Changes to Pancreatic Cells

A team of scientists led by a Northwestern University biomedical engineer has developed a way to examine cell biopsies and detect never-before-seen signs of early-stage pancreas cancer, as per a new paper published online by the OSA journal Optics Letters.

Though the new technique has still not proven effective in double-blind clinical trials, it may one day help diagnose cancers of the pancreas and, potentially, other organs at their earliest and most treatable stages, before they spread.

A team from Northwestern and NorthShore University HealthSystem (NorthShore) describes the first application of the new technique, which they call "partial wave spectroscopic microscopy." This technique allows them to examine cell samples taken from people who have undergone screening for pancreas cancer to detect signs of the disease.

Pancreas cancer is typically diagnosed by hospital pathologists who look for telltale changes to the morphology of pancreatic cells when they examine cell biopsies under the microscope. The problem is that in the early stages of cancer, a number of early-stage cancer cells appear normal. By the time the malignant cells undergo observable changes, it appears to be too late in the disease progression for effective therapy.

In fact, only 7 percent of people with pancreas cancer are diagnosed in the earliest stages of the disease, when the cancer is still confined to its primary site. More than half of all people with the disease are not diagnosed until it has already metastasized......... Posted by: Andria      Read more         Source

February 20, 2009, 6:07 AM CT

When should you stop doing PSA testing?

Although widespread Prostate-Specific-Antigen (PSA) testing has undoubtedly decreased prostate cancer mortality, is there a point of diminishing returns? According to a research findings published in the April 2009 issue of The Journal of Urology, researchers found that in a subgroup of elderly men, among those who were 75 years old or older and had a PSA below 3 ng/ml (nanograms per milliliter), none subsequently died of prostate cancer. The discontinuation of routine PSA screening in these men may not increase the rates of undetected lethal disease, and could avoid potentially unnecessary treatments and reduce diagnostic costs.

Because PSA screening can find cancers that may become life-threatening in 5 to 25 years, there has been increased usage of the test in 40 to 50-year-olds. But the test can also discover cancers that never become life-threatening, perhaps in up to 30% of the cases. Many men who are older than 75 undergo continued PSA screening, potentially leading to unnecessary treatment since death from other causes is more likely than death from prostate cancer.

The study conducted by scientists from the Baltimore Longitudinal Study of Aging (National Institute on Aging, National Institutes of Health) and the Department of Urology at Johns Hopkins School of Medicine involved 849 men (122 with and 727 without prostate cancer) with serial PSA measurements. Researchers found that for men over 75 with PSA < 3ng/ml, none died of prostate cancer and only one developed high-risk prostate cancer. In contrast, men of all ages with a PSA ≥3.0 ng/ml had a continually rising probability of death from prostate cancer......... Posted by: Andria      Read more         Source

February 18, 2009, 6:20 AM CT

New method to predict colorectal cancer recurrence

A preliminary report shows that genetic testing may help identify a marker in lymph nodes that is linked to an increased risk of colorectal cancer recurrence among patients in whom conventional testing indicates that those lymph nodes show no evidence of cancer spread, as per a research studyin the February 18 issue of JAMA

Metastasis of tumor cells to regional lymph nodes is the single most important prognostic factor in patients with colorectal cancer. Recurrence rates increase from approximately 25 percent in patients with lymph nodes free of tumor cells as determined by biopsy (pN0 colorectal cancer) to approximately 50 percent in patients with four or more lymph nodes with metastases, as per background information in the article.

"Given the established relationship between lymph node metastasis and prognosis, recurrence in a substantial fraction of patients with pN0 colorectal cancer suggests the presence of occult [undetected] metastases (pN0 [mol+]) in regional lymph nodes that escape [biopsy] detection. On the other hand, patients with pN0 colorectal cancer who are free of lymph node metastases appears to be at lowest risk for developing recurrent disease. Thus, a more accurate evaluation of occult metastases in regional lymph nodes in patients with pN0 colorectal cancer could improve risk stratification in this clinically heterogeneous population," the authors write......... Posted by: Andria      Read more         Source

February 12, 2009, 5:46 AM CT

New culprit for prostate cancer?

Howard Hughes Medical Institute scientists have identified a new biological marker present in the urine of prostate cancer patients that indicates whether the cancer is progressing and spreading.

In experiments published in the February 12, 2009, issue of the journal Nature, the researchers identified 10 metabolites that become more abundant in prostate cells as cancer progresses. Their studies showed that one of these chemicals, sarcosine, helps prostate cancer cells invade surrounding tissue.

HHMI investigator Arul Chinnaiyan and his colleagues at the University of Michigan showed that as prostate cancer develops and progresses, sarcosine levels increase in both tumor cells and urine samples, suggesting that measurements of the metabolite could aid in non-invasively diagnosing the disease. Scientists might also be able to inhibit prostate cancer's spread by designing drugs that manipulate the sarcosine pathway.

The study is the first to analyze the levels of more than 1,000 different metabolites in human tumors. Researchers know that cells undergo complex changes as cancer develops and progresses to metastatic disease. Chinnaiyan's lab, which has extensively analyzed how genes and proteins in prostate cancer cells reflect these changes, thought that profiling cells' metabolites would offer an even more "holistic picture of the molecular alterations that occur," he said......... Posted by: Andria      Read more         Source

January 8, 2009, 9:23 PM CT

Why bladder cancer is deadlier for some

Bladder cancer is much more likely to be deadly for women and African-Americans, but the reasons long believed to explain the phenomenon account for only part of the differences for such patients in comparison to their white and male counterparts, as per results reported in the Jan. 1 issue of the journal Cancer

The results present a stark question for doctors and patients: If age, tumor type, and stage of the disease upon diagnosis don't account for all the increased lethality of the disease in women and African-Americans, then what does?

It's a gaping question facing scientists who have long confronted an irony of bladder cancer, the fifth-most-common type of cancer in America. The disease is more lethal in those patients who are less likely to get it.

Men are more than three times as likely as women to get the disease, and white people are nearly twice as likely to get the disease as African-Americans. Yet, once the disease is present, it's far deadlier in women and in African-Americans anywhere from 73 percent to 114 percent more deadly in the first year after diagnosis, depending on the group.

In the Cancer paper, researchers and physicians at the University of Rochester Medical Center show for the first time that the factors traditionally believed to be responsible for the differing course are responsible for only about one-third of the difference between white men and women, and up to two-thirds of the difference between African-Americans and their white counterparts......... Posted by: Andria      Read more         Source

December 23, 2008, 10:27 PM CT

Destabilizing cancer cells in kidney cancer

Kidney cancer is typically without symptoms until it has spread to other organs, when it is also the most difficult to treat. Newer chemotherapies show great promise for extending survival during later disease stages, but they can also be highly toxic.

In one of the first discoveries of its kind, UC Davis Cancer Center scientists have identified ways to block a cancer gene's own repair mechanism and, in so doing, help make chemotherapy for kidney cancer more effective and better tolerated. The outcome is reported in the current issue of Cancer Biology and Therapy

"Cancer cells are notorious in their ability to rapidly create copies of themselves. While the latest medications slow down that process, they do not tend to be curative and have a number of side effects," said Robert Weiss, a UC Davis professor of nephrology and chief of nephrology at the Sacramento VA Medical Center. "We wanted to find ways to help make chemotherapeutics as effective as possible at the lowest doses possible".

Newer medications work by destabilizing cancer cells at the DNA level, which reduces their ability to replicate. Knowing that the p21 gene has an important role in restoring cancer cell DNA and potentially circumventing the benefits of those therapys, Weiss sought to identify compounds that could interrupt this pathway......... Posted by: Andria      Read more         Source

December 22, 2008, 9:32 PM CT

E. coli engineered to produce anti-cancer drugs

Scientists from the UCLA Henry Samueli School of Engineering and Applied Science have taken a major step forward in the field of metabolic engineering, successfully using the bacterium Escherichia coli to synthesize a class of natural products known bacterial aromatic polyketides, which include important antibiotic and anticancer drugs.

Natural products are pharmacologically or biologically potent chemical compounds produced by living organisms; a number of are the active ingredients in pharmaceuticals. Bacterial aromatic polyketides include the antibiotic tetracycline and the compound doxorubicin, used in the therapy of breast and other cancers.

Because a number of of these natural products are synthesized by organisms that are difficult to collect, grow and maintain, scientists have sought to produce them using simpler organisms like E. coli, whose fast growth, variety of genetic tools and well-understood metabolism make it an ideal host for engineering and mass producing these compounds.

While turning E. coli into a microbial factory for natural products has been highly successful, resulting in the production of groups of drugs that include antibiotics like erythromycin and vancomycin, as well as terpenes and alkaloids, attempts to synthesize bacterial aromatic polyketides had previously been hindered by the compounds' complicated assembly process......... Posted by: Andria      Read more         Source